So many days passed and still, you didn’t receive an EX Raid Pass? Don’t Worry, Here’s a Comprehensive guide how to Trigger EX Raids, Triggering is based on S2 cells, gym eligibility and expected player and raiding activity.

The Guide will go through the following process!

What do we know about EX Raids

Discovering your local S2 cell geometry

Finding eligible gyms

Collecting raid eligibility points

Raiding where and when it matters

Before triggering let’s take a look at what we know about EX Raids so far

What do we know about EX Raids?

EX Raids are created based on Level 12 S2 cells. Each cell can only host one EX raid per “invitation cycle”

EX Raids can only happen at gyms that are either sponsored or placed in a park-related OpenStreetMap tag

Gyms that hosted a raid before can and will host an EX Raid again, there is no diminishing returns

Ex Raids can be triggered and there could be some randomness to it

An EX Raid is triggered only if the gym reaches a minimum amount of raid activity since the last invitation cycle

So now we have some basics about EX Raids, Let begin the Triggering!

Discovering your local S2 cell geometry

EX Raids can only occur once inside each S2 cell that passes over your local area. A question might come to your mind

What is S2 Cell?

Level 12 S2 Cell

S2 cells are a simple mathematical way to describe a sphere’s geometry. S2 cells come in different sizes, often denoted as levels, and they are often used by developers to create zones on spherical objects, like the planet Earth.
Niantic uses S2 Cell to control weather, deploy Gyms, Pokestops, Pokemon Hatch Location, etc
Now we know what S2 Cell is, let’s move further in discovering your S2 Cell, We’ll discover your S2 Cell with the help of an incredible tool that draws Level 12 cells over a Google Map created by A company named Sidewalk Labs.

Follow the Below steps to Discover your local S2 cell geometry

Set the Parameters in the Box to min level 12, max level 12, max cells 10

Using one of the drawing tools in box (Square or Circle) select a map area where you want to visualize Level 12 S2 cells

Wow! Now you have your Local S2 Cells, remember that an EX Raid can only occur once per cell per cycle. Raiding 1000 gyms inside one cell doesn’t benefit you as much as raiding a dozen of eligible gyms in a higher number of cells.

Finding eligible gyms

As We know that EX Raids can only happen at gyms that are either sponsored or placed in a park-related OpenStreetMap tag
In this Guide, we’re focusing on gyms located in parks and similar areas. The easiest way to check what the game considers to be a park is to use a tool called Overpass Turbo. Overpass Turbo is a free online tool that can plot locations of various OpenStreetMap tags.

Finding eligible EX Raid areas on OpenStreetMap using Overpass Turbo

Follow the Below steps To find eligible gyms using Overpass.

Head over to Overpass using this Special Link (It Contains the query that’s needed to plot eligible areas, The complex query we use was written by Tntnnbltn)

Locate to your Area

Click “Run” from the top left corner of your Window

Observe and make note of the areas, these are the areas where you will find EX raid eligible gyms.

Only gyms that fall into these areas are eligible for EX Raids.

So here we completed the Step 2 and here comes the major part!

Collecting raid eligibility points

So now we have S2 Cell, Eligible Gyms, and the next step is collecting Raid Eligibility points.
The Following factors influence the chance of EX Raid spawning:

Cumulative raiding activity in the last 8-9 days

Cumulative raiding difficulty in the last 8-9 days

Relative raiding activity in regards to other gyms in the area

In order to trigger an EX Raid, a certain minimum Raid Points must be achieved, At this point, we do not know the minimum value, but research suggests that it could be around 20-25 Level 4 raids with 5 players.

Raiding where and when it matters

Raid only and exclusively gyms that are located in parks

Share and disseminate this information to your local raiding group.

Always try to raid as a group and don’t shy away from difficult raids

Be aware of gyms and their S2 placement — after you’re done with one cell, move over to another cell

Remember that there could be luck and randomness involved which we are not aware of

Furthermore, in every S2 cell where an EX Raid takes place, you’re competing with every other active raider. Therefore, a branching strategy is advised: cover as many S2 cells as possible in order to increase your potential chance of getting an invite if an EX Raid occurs there.